Experimental Study On The Hydraulic Performance Of A Submerged Plate For Wave Dissipation

Traditional wave dissipation structures have been playing an important role in the development of ocean engineering and have exerted a certain effect on resisting waves. However, they have many disadvantages such as high cost, complex technology requirements and long construction process. Instead, the new open-type wave dissipation structure can effectively make up for the shortage and is drawing people’s attention and concern.As an open-type structure, submerged horizontal plate has many advantages such as saving materials, easy installation and eco-environmental friendliness. It can resist the invasion of waves against marine structures in most cases and meet the needs of modern marine engineering. Its performance of dissipation for regular waves and particularly for irregular waves is studied in the paper by conducting a series of physical model experiments which are conducted in three different water depths and the submerged depth of the plate is also changed in each water depth.As for experiments of regular waves, the influence of submerged depth and the relative plate width on reflected coefficients and transmission coefficients is analyzed. The results show that the reflection coefficient is slightly affected and the plate’s reflection ability is limited and hard to be improved. Instead, the bigger the relative plate width, the smaller the transmission coefficient. That is to say, the smaller the wavelength, the smaller the transmission coefficient. It is demonstrated that the submerged plate is applicable for dissipating short waves.The focal point of this paper is to study the dissipation effect of irregular waves by submerged horizontal plate. The basic characteristics of incident wave spectrums, reflected wave spectrums and transmitted wave spectrums are analyzed. The energy of reflected wave and transmitted wave is weighed by the zero moment of their spectrums, which is the area of the wave spectral curve, and then the wave dissipation performance is known as the ratio of transmission spectrum energy to the incident spectrum energy. The transmission spectrums are fitted and fitted expressions described by experimental initial incident waves and its related parameters are　presented. The fitting result shows that the fitted spectrums can match well with the experiment spectrums and their related parameters are close.